audk/MdePkg/Library/BaseLib/Ia32/RShiftU64.c

39 lines
1.0 KiB
C

/** @file
64-bit logical right shift function for IA-32
Copyright (c) 2006 - 2007, Intel Corporation<BR>
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
//
// Include common header file for this module.
//
#include "CommonHeader.h"
UINT64
EFIAPI
InternalMathRShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
{
_asm {
mov cl, byte ptr [Count]
xor edx, edx
mov eax, dword ptr [Operand + 4]
test cl, 32
cmovz edx, eax
cmovz eax, dword ptr [Operand + 0]
shrd eax, edx, cl
shr edx, cl
}
}